Making an entrance

Peri formwork is helping Bam Nuttall make space for a sliding dock wall at the Rosyth submarine base in the Firth of Forth. NCE reports.

At the Babcock-owned Rosyth site, contractor Bam Nuttall is part way through a project to widen the entrance from the Firth of Forth into the non-tidal basin. This is to allow large prefabricated sections of the Royal Navy’s next generation of aircraft carrier to be floated through for final completion.

The gated entrance to the inner non-tidal basin has to be widened by 4m from 38.2m to 42.1m to accommodate the new carriers. The new sliding dock gate must be able to retract fully into its own chamber. To accommodate this extra length an 8m section is being trimmed from the entrance on the northern side while a 4m extension is added to the southern side.

As part of the construction process the Bam Nuttall team is breaking out a large part of the existing north quay down to the dolerite outcrop 25m below the top of the harbour side and 20m below the surface of the Firth of Forth.

Single sided climbing system

For the construction of the new gated entrance Bam Nuttall came to formwork specialist Peri to source its formwork requirements. SKS, the single sided climbing system which is the choice of system for dam, weir and lock structures was coupled with Trio wall formwork.

SKS was used as the concrete pressure imposed on the forms during construction can only be taken on one side requiring the load to be transferred back in to the structure via the platform system.Bam Nuttall sub agent John Slaven says: “Construction of the new entrance structures was on the critical path of our programme.

“Once the system was erected it was easy and quick to turnaround, helping us beat our programme. Peri also provided good technical support throughout. I would not hesitate in using this system again.”

Mabey Hire’s Frami panels are being used to form a basement retaining wall at a site in the north west. NCE reports on lightweight, easily manoeuvrable formwork which can be assembled by hand with minimal mechanical help.

Have your say

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Please note comments made online may also be published in the print edition of New Civil Engineer. Links may be included in your comments but HTML is not permitted.

A subscription to New Civil Engineer...

...offers in-depth analysis of the news that matters, interviews and commentary
from leading industry players and special reports on key events, it’s the resource that helps you make better business decisions.